(a) Field of the Invention
The present invention relates to a disk cartridge opposite insertion preventing mechanism for correctly limiting the direction of insertion of a disk cartridge containing an optical disk or the like into an apparatus or casing body of a disk cartridge.
(b) Description of the Prior Art
A conventional disk cartridge containing an optical disk has such a structure as shown in FIGS. 4 and 5. That is, terraced grooves 2 for positioning the disk cartridge 1 are provided on opposite sides of the forward end portion 6 of the disk cartridge 1; notch portions 3 used for carrying the disk cartridge 1 are provided on opposite sides of the rear end portion of the disk cartridge 1; and light-transmission windows 4 for detecting light are provided near the notch portions 3, respectively.
When, for example, the disk cartridge 1 is inserted into a carrying tray used in an automatic disk exchanger or the like, the light-transmission windows 4 or notch portions 3 of the disk cartridge 1 are detected by transmission type or reflection type sensors to thereby judge whether the direction of insertion of the disk cartridge 1 is normal or not. It is therefore necessary to provide sensors for detecting the light-transmission windows 4 or notch portions and attendant electric circuits therewith.